JP52122645 (DAINIPPON PRINTING) discloses the preparation of sterilized boiled rice, by filling a container with rice and 40% to 55% water in heat-resistant pouches or cans, sealing them tightly, and cooking and sterilizing them simultaneously by heating with rotating.
FR2502907 (BUITONI) discloses the production of precooked solid food, especially pasta products and rice, by precooking the food in acidulated water, cooling in acidulated water, draining off excess water, oiling, insertion into flexible containers and heat sterilizing the sealed containers.
JP3087153 (ASAHI CHEM IND) discloses the preparation of packaged processed rice with good preservability, by heating rice, controlling its acidity to within a pH range of 3.5 to 6 and its moisture content to within 20% to 30%, and preventing grains from aggregation by light crushing.